Device for burying rigid wall pipe

ABSTRACT

A tractor mounted device for directly burying rigid wall metal pipe below the surface of the ground. A trench is formed by an upstanding ripper shank and the pipe is inserted to the bottom of the trench through an elongated guide member carried rearwardly of the shank. The guide member includes a sloping S-shaped tube carried on a box shaped frame. The frame has side panels which support the walls of the trench between the shank and the terminal end of the guide tube. The tube is curved such that the pipe is subjected to minimal bending stress and has a reverse bend at the terminal end which straightens the pipe so that it will lie parallel with the bottom of the trench.

[ Dec. 23, 1975 DEVICE FOR BURYING RIGID WALL PIPE [75] Inventor: Roger L. Sprenkel, Pleasanton,

Calif.

[73] Assignee: American Tractor Equipment Corporation, Oakland, Calif.

22 Filed: July 31, 1974 211 App]. No.: 493,233

[52] US. Cl. 61/72.4

7/1974 Blankenship 61/724 X 3,824,798 7/1974 Shiroyama et a1, 6l/72.4

Primary ExaminerDennis L. Taylor [5 7] ABSTRACT A tractor mounted device for directly burying rigid wall metal pipe below the surface of the ground. A trench is formed by an upstanding ripper shank and the pipe is inserted to the bottom of the trench through an elongated guide member carried rearwardly of the shank. The guide member includes a sloping S-shaped tube carried on a box shaped frame. The frame has side panels which support the walls of the trench between the shank and the terminal end of the glide tube. The tube is curved such that the pipe is subjected to minimal bending stress and has a reverse bend at the terminal end which straightens the pipe so that it will lie parallel with the bottom of the trench.

12 Claims, 8 Drawing Figures US. Patent Dec. 23, 1975 Sheet 1 of2 Sheet 2 of 2 US. Patent Dec. 23, 1975 DEVICE FOR BURYING RIGID WALL PIPE BACKGROUND or THE INVENTION Tractor pulled cable laying plows have been in use for some time in which a ripper shank plows a trench or furrow while a cable is fed to the bottom of the trench through a trailing feed tube. These plows may also be used for burying the smaller sizes of flexible pipe and conduit.

Generally the cable is stripped from a reel carri d by the tractor and is fed vertically through the feed tube to the bottom of the trench. The cable is flexed through relatively short radius bends at the entrance and exit of the feed tube. This causes no problem with the flexible cable but precludes the use of this equipment for laying rigid wall pipe which would collapse if bent through such short radii.

SUMMARY OF THE INVENTION It is a principal object of the present invention to lay rigid wall pipe below the surface of the ground by bending the pipe through long radius curves and then straightening the pipe so that the pipe will remain under the ground without any residual stress.

Another object is to provide a device which will plow a trench and guide the pipe to the bottom of the trench such that the pipe is buried in a continuous fashion.

It is another object to guide the pipe through an encircling guide tube wherein dirt will not interfere with the passage of the pipe through the tube.

A further object is to directly bury pipe which has been prejoined along a path on the surface of the ground by moving a tractor adjacent said path and supporting on the tractor a pipe elevating means, a trench forming shank and a pipe depressingguideway wherein the prejoined sections of pipe are elevated and depressed into the trench in an efficient, continuous fashion.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the preferred embodiment of the present invention illustrating the relationship of the pipe, tractor, plow shank and pipe guideway when used for laying rigid wall pipe below the surface of the ground.

FIG. 2 is a side elevational view of the plow shank and elongated pipe guide member of the device in FIG. 1.

FIG. 3 is a detailed layout of the geometry of the guide tube.

FIG. 4 is an elevational section taken substantially along the plane of line 44 of FIG. 2.

FIG. 5 is an elevational section taken substantially along the plane of line 55 of FIG. 2.

FIG. 6 is a plan sectional view taken substantially along the plane of line 66 of FIG. 2.

FIG. 7 is a plan sectional view taken substantially along the plane of line 7 7 of FIG. 2.

FIG. 8 is a fragmentary elevational view taken substantially along the plane of line 8-8 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention has successfully been used for directly burying 3 inch [.D. A inch steelwall pipe at a depth of 34 feet below the surface of the grouru utiliz' ing the structure shown in the drawings.

As shown in FIG. 1, tractor 12 has mounted thereon device 13 for burying rigid wall pipe 14 below the surface of the ground 16. An upstanding shank 17 is carried adjacent tractor 12 for side-to-side swinging movement, up and down movement, and side-to-side pivotal movement, and is formed for ripping a pipe burial trench 18 in the ground. An elongated, planar pipe guide or guideway member 19 having a forward end and a trailing end is carried rearwardly of shank l7 and has'an S-shaped pipe guiding passageway or guideway 21 through which pipe 14 is inserted into trench l8. S-shaped guideway 21 has a first curved section 22 formed for bending and depressing pipe 14 into trench 18, a second curved section 23 consecutive with the first curved section 22 and having a reverse curvature thereto formed for bending pipe 14 wherein the pipe lies adjacent to the bottom of trench 18, and a third curved section 24 consecutive with the second curved section 23 and having a reverse curvature thereto formed for bending and straightening pipe 14 such that the pipe will lie straight in trench 18.

Pipe 14 is formed of pipe sections prejoined along path 26 and tractor 12 moves along a route adjacent to path 26. Tractor 12 is equipped with a full range offset attachment 27 which supports plow shank 17 in alignment with path 26. Full range offset 27 allows plow shank 17 to be situated outside the track of the tractor and also has linkage and power cylinders to vary the penetration and attitude of the shank. Such an attachment is mounted on tractor 12 through vertical hinge pin 28 and is swingable thereabout upon actuation of offset cylinders 29. Lift cylinders 31 are operable on link 32 to vary the vertical displacement of rear bracket 33 while pitch cylinder 34 is connected to rear bracket 33 through pin 36. Shank bracket 37 is hinged to rear bracket 33 through vertical hinge pin 38 and is movable thereabout upon actuation of tiller cylinders 39. Shank 17 is carried on shank bracket 37 by removable pins 41. Thus, actuation of the various cylinders will alter the depth of penetration and draft angle of shank 17 as well as control the offset from tractor 12. While this attachment has been used on previous cable plows, it finds particular usefulness where the pipe is prejoined on the ground and the shank and guideway have to accurately follow the path of the pipe.

Shank 17 depends from shank bracket 37 to a tooth 42 which defines the bottom of trench 18. Between bracket 37 and tooth 42, shank 17 has an aperture 43 through which pipe 14 passes to the trailing guideway member 19. The leading edge 44 of guideway member 19 is hingedly carried on the trailing edge of shank 17 through hinge pins 46 and allows guideway 19 to track shank 17 in trench 18.

Elongated guideway 19 is formed of a curved tube 51 extending rearwardly of aperture 43 to a position along the bottom of trench 18. Tube 51 is supported by a box frame 52 formed by a series of panels extending rearward of the leading edge of guideway 19. The sides of box frame 52 serve to support the walls of the trench between shank l7 and the terminal end of tube 51. Side panels 53a, 53b and 530 are spaced by top panels 540 and 54b and by bottom panel 56 such that box frame 52 has a narrow configuration similar to the configuration of shank 17. By having a transverse width which is only slightly larger than pipe 14 (in the order of less than As mentioned, pipe 14 is bent in curved tube 51 as it is depressed into trench 18. Since the bending of the pipe requires a force which is supplied by the forward movement of the guideway and the tractor, it is desired to make these bends as gentle as possible. Similarly, advantage is gained by having the pipe enter the guideway on an inclined slope wherein the pipe will be initially moving along a downward course into the trench.

As shown in FIG. 3, geometry of the tube of the aforementioned embodiment was chosen to use relatively long radii of curvature of the curved sections. Thus, at the leading end of the tube, a straight section 61 of 24 inches in length and inclined downward 10 from the horizontal serves to receive the pipe on an inclined slope. The first curved section 22 continued for 61 inches and had a radius of curvature of 500 inches. A transitional straight section 62 of 31 inches led into the second curved section 23. The second curved section 23 formed the major length of the guideway and extended 207 inches and had a radius of curvature of 700 inches. The trailing end of the second curved section 23 has an ascending portion 63 for 24 inches. The third curved section 29 has a curvature inverse to the second curved section and serves to bend the pipe on a declining path from the ascending path of portion 63. This straightens the pipe so that it will lie parallel with the bottom of the trench and superjacent thereto. Third section 24 has a radius of 700 inches over a 24 inch span and terminates in a straight portion 64 of 24 inches. There is a drop of 58 inches from the entrance to the exit of tube 51. While the dimensions given are only illustrative, and should not be limiting, they do serve to present some of the criteria for forming an acceptable guideway for 3 inch I.D. steel wall pipe. Furthermore, they illustrate the desirableness of having an initial inclined slope and the long radii of curvature of the curved sections with the important feature of removing the bend from the pipe at the terminal end so that it will lie straight in the trench without any residual bending stress and thus overcomes the tendency of unstraightened pipe to spring out or work its way out of the trench.

In use, pipe sections are joined into a continuous pipe 14 along the surface of the ground. Tractor l2, trailing ripper shank 17 and elongated guide member 19 move along a route adjacent the pipe. Elevating means 66 formed by roller 67 on shaft 68 is carried on the blade support structure 69 at the forward end of the tractor and is vertically movable by the blade elevating mechanism 71. This elevating means 66 serves to pick up the preceding length of pipe and feed it at the proper inclined angle through aperture 43 into tube 51. On the span of pipe between roller 67 and tube 51 any adhered dirt may be removed and the pipe will remain clean while inserted through the encircling tube 51 into the trench. This reduces the sliding friction between the tube and pipe.

From the foregoing, it will be seen that an improved device of laying rigid wall pipe has been disclosed in which the pipe is buried below the surface of the ground in an efficient and continuous manner.

I claim:

1. A tractor supported apparatus for burying a continuous length of rigid wall pipe below the surface of the ground, comprising: an upstanding shank having a tooth at the lower end thereof and constructed to rip a pipe burial trench in the ground; pivot means mounting the shank to the tractor for side-to-side swinging movement, up and down movement, and side-to-side pivotal movement of the shank; an elongate, substantially flat, planar pipe guide member having a forward end and a trailing end, said forward end pivotally connected to the shank for trailing movement of the guide member after the shank in a trench; an elongate, generally S- shaped, open-ended pipe guiding passageway in the guide member and extending throughout the length of the guide member, said S-shaped passageway including a pipe receiving portion at the forward end of the guide member extending upwardly at an angle of about 10 relative to the horizontal to receive a length of rigid wall pipe therein at an angle to the horizontal, a first curved section curving downwardly from the pipe receiving portion for bending and depressing a length of pipe into the trench, a second curved section connected to the first curved section and having a curvature inverse to the curvature of the first section and having a trailing end portion which ascends relative to the bottom of the trench for bending the pipe and disposing it near the bottom of the trench, and a third section connected to the second section and including a straight portion extending substantially parallel to the bottom of the trench to bend and straighten the pipe and discharge the pipe into the bottom of the trench, so that the pipe will lie straight in the trench free of residual bending stresses.

2. The apparatus as defined in claim 1, wherein said passageway further includes a first straight section connected between and joining the first and second curved sections, and said third section includes a third curved portion having a curvature inverse to the second curved portion and terminating in said straight portion.

3. The apparatus as defined in claim 1 and wherein, said passageway is formed by a continuous tube through which said pipe is inserted from the surface of the ground to the bottom of the trench.

4. The apparatus as defined in claim 1 and wherein, said elongated guide member has spaced apart, parallel side panels which extend rearwardly of said shank and are adapted to support the walls of said trench.

5. The apparatus as defined in claim 4 and wherein, said ripping tooth at the lower end of the shank defines the bottom of said trench, said guide member is supported by said side panels and terminates at a point immediately superjacent said bottom of said trench.

6. The apparatus as defined in claim 1 and wherein, said shank has an aperture in alignment with the forward end of said passageway through which said pipe is inserted to the trailing guide member.

7. The apparatus as defined in claim 1 and wherein, the transverse width of said shank and said guideway are similarly of a narrow configuration and are in the order of less than two times the diameter of the pipe.

8. The apparatus as defined in claim 1 and wherein the angle of inclination of said passageway from the surface of the ground to the bottom of said trench is less than 30, and the length of the curved portions of the curved sections is a substantial majority of the length of said passageway whereby the pipe is subjected to minimal sliding friction as it is inserted through said passageway.

9. The apparatus as defined in claim 8 and wherein the length of radius of curvature of the curved sections is greater than the length of said passageway such that the pipe is subjected to minimal bending stress.

10. The apparatus as defined in claim 1 and wherein, an elevating means is carried by said tractor forward of 6 vertical position by a blade elevating mechanism of the tractor.

12. The apparatus as defined in claim 1 and wherein power operated elevating mechanism and lateral swinging mechanism are connected with said pivot means to properly position said shank and guide member. 

1. A tractor supported apparatus for burying a continuous length of rigid wall pipe below the surface of the ground, comprising: an upstanding shank having a tooth at the lower end thereof and constructed to rip a pipe burial trench in the ground; pivot means mounting the shank to the tractor for side-to-side swinging movement, up and down movement, and side-to-side pivotal movement of the shank; an elongate, substantially flat, planar pipe guide member having a forward end and a trailing end, said forward end pivotally connected to the shank for trailing movement of the guide member after the shank in a trench; an elongate, generally S-shaped, open-ended pipe guiding passageway in the guide member and extending throughout the length of the guide member, said Sshaped passageway including a pipe receiving portion at the forward end of the guide member extending upwardly at an anGle of about 10* relative to the horizontal to receive a length of rigid wall pipe therein at an angle to the horizontal, a first curved section curving downwardly from the pipe receiving portion for bending and depressing a length of pipe into the trench, a second curved section connected to the first curved section and having a curvature inverse to the curvature of the first section and having a trailing end portion which ascends relative to the bottom of the trench for bending the pipe and disposing it near the bottom of the trench, and a third section connected to the second section and including a straight portion extending substantially parallel to the bottom of the trench to bend and straighten the pipe and discharge the pipe into the bottom of the trench, so that the pipe will lie straight in the trench free of residual bending stresses.
 2. The apparatus as defined in claim 1, wherein said passageway further includes a first straight section connected between and joining the first and second curved sections, and said third section includes a third curved portion having a curvature inverse to the second curved portion and terminating in said straight portion.
 3. The apparatus as defined in claim 1 and wherein, said passageway is formed by a continuous tube through which said pipe is inserted from the surface of the ground to the bottom of the trench.
 4. The apparatus as defined in claim 1 and wherein, said elongated guide member has spaced apart, parallel side panels which extend rearwardly of said shank and are adapted to support the walls of said trench.
 5. The apparatus as defined in claim 4 and wherein, said ripping tooth at the lower end of the shank defines the bottom of said trench, said guide member is supported by said side panels and terminates at a point immediately superjacent said bottom of said trench.
 6. The apparatus as defined in claim 1 and wherein, said shank has an aperture in alignment with the forward end of said passageway through which said pipe is inserted to the trailing guide member.
 7. The apparatus as defined in claim 1 and wherein, the transverse width of said shank and said guideway are similarly of a narrow configuration and are in the order of less than two times the diameter of the pipe.
 8. The apparatus as defined in claim 1 and wherein the angle of inclination of said passageway from the surface of the ground to the bottom of said trench is less than 30and the length of the curved portions of the curved sections is a substantial majority of the length of said passageway whereby the pipe is subjected to minimal sliding friction as it is inserted through said passageway.
 9. The apparatus as defined in claim 8 and wherein the length of radius of curvature of the curved sections is greater than the length of said passageway such that the pipe is subjected to minimal bending stress.
 10. The apparatus as defined in claim 1 and wherein, an elevating means is carried by said tractor forward of said guide member and is adapted to elevate preceding pipe sections wherein the pipe will enter the passageway at the proper inclined angle.
 11. The apparatus as defined in claim 10 and wherein, said elevating means is a roller carried on a shaft connected to a blade support structure at a forward end of the tractor and is positioned in the proper vertical position by a blade elevating mechanism of the tractor.
 12. The apparatus as defined in claim 1 and wherein power operated elevating mechanism and lateral swinging mechanism are connected with said pivot means to properly position said shank and guide member. 